The theories behind who and what attacked Twitter and Facebook yesterday — causing intermittent outages at each — are flying like so many tweets across the Internet. The prevailing theory suggests that the outage was due to a cyber skirmish stemming from simmering tensions between Russia and Georgia.
CNet and CNN place blame for the incident on an elaborate, politically motivated vendetta timed to coincide with the one year anniversary of the Russia-Georgia war, a brief but costly skirmish in August 2008 accompanied by cyber attacks on Georgian government Web sites. In short: the outage at Twitter (and to a lesser extent Facebook & LiveJournal) was due to an effort to silence an anti-Russian blogger from Tbilisi who has been calling attention to a recent resurgence of tensions in the region.
CNet cites Facebook’s Chief Security Officer Max Kelly saying that a political blogger using the online name "Cyxymu" – who had accounts on Twitter, Facebook, LiveJournal and Google’s Blogger and YouTube — was the target of a denial of service attack, and that the attack against him was what caused the outages.